1. Electric Current
Chapter 6-2

2. Electric Circuit A closed path through which electrons can flow
Electrons flow because of a difference in potential
When a switch is turned on it causes electron to flow

3. Flowing Electrons
Remember that static electricity is the build up of electrons
When the static charge causes a spark the flow of electrons that is created is very short
Not long enough to run a light or a computer

4. The electrons always flow from where there are more electrons (higher potential) to fewer electrons (lower potential)
Static discharge quickly balances out the electrons and there is no more difference in potential

5. Role Play Image

6. Current, I The flow of electrons
The amount of current depends upon the number of electrons passing every second
Measured in Amperes, Amps, A
Measured with an ammeter

7. Ampere One ampere is one coulomb of charge passing every second
One coulomb is 6.24 billion billion electrons

8. Potential Difference (Voltage)
The difference in potential (the energy of the electrons) between two different places
Measured in volts (V)
Sometimes called voltage
Measured with a voltmeter
Doesn’t depend upon the number of electrons only the energy the electrons carry

9. Batteries
Current must maintain a difference in potential or the current will stop
Batteries is a device that maintains that difference in potential

10. Batteries supply the energy to keep the electrons moving, they don’t supply the electrons

11. Dry cells-a positive electrode, a negative electrode, and a moist paste to pass the electrons
Wet cells-a positive plate, a negative plate, and a liquid solution to pass the electrons

12. Resistance, R The opposition to the flow of electrons
Measured in Ohms, W
Copper is an excellent conductor because it has low resistance

13. Good & Bad Resistance
Toasters, hair dryers, Christmas lights
Wiring

14. Ohm’s Law
Determines a relationship between voltage, current and resistance

15. If the resistance increases the current decreases
A greater voltage in a circuit causes the current to increase

16. George Simon Ohm
German physicist found experimentally

17. The current in a metal conductor is directly proportional to the potential difference across it and inversely proportional to the resistance, Ohm’s Law
V = IR